Noise attenuating stethoscope



May 23, 1967 F. R. BOWEN, JR 3,321,041

NOISE ATTENUATING STETHOSCOPE Filed April '22, 1966 2 Sheets-Sheet 1FRANK R. BOWEN, Jr.

I/VVE/V r0? y 1957 F. R. BOWEN, JR 3,321,041

NOISE ATTENUATING STETHOSCOPE Filed April 22, 1966 Sheets-Sheet 2 FRANKR BOWEN, Jr.

INVENTOI? United States Patent 3,321,041 NOISE ATTENUATING STETHOSCOPEFrank R. Bowen, Jr., Charlotte, N.C., assignor to John M. Medlin,Charlotte, N.C. Filed Apr. 22, 1966. Ser. No. 544,527 4 Claims. (Cl.181-24) This invention relates to stethoscopes and, more particularly,to an improved stethoscope for use in highintensity noise areas.

For the most part, when stethoscopes are being used by a doctor or amedical technician, the person being examined is either in the doctorsoflice or in some other area where the ambient noise level is at asufiiciently low level so as not to interfere with the sounds picked upby the stethoscope. It should be obvious that, when a doctor islistening for faint heart murmurs or for rales in the chest, the maximumdegree of quiet is required as these are the sounds that are easiest tomiss. However, there are many instances where the person to be examinedis found in an area where the intensity of the noise is of such a highlevel as to render it impossible for the examiner to accurately diagnosethe condition of the patient due to the fact that the aberrant noiseinterferes with and covers over the sounds being sought by the examiner.

For example, if an accident were to occur in the boiler room or engineroom of a ship on the high seas and the patient were on the deck, goodmedical techniques dictate that the injured person should not be movedbefore the extent of the injury has been determined by the physician.Under these circumstances, it would be impossible to detect the patientsheart beat in the presence of the extremely high'ambient noise level.Thus, in violation of good medical practice, the patient would have tobe moved from the area of high noise level before the stethoscope couldbe effective in noting, for example faint heart beats.

Still another area in which my device finds particular applicability isin the techniques of battle-field medicine. Specifically, for example,when a soldier is wounded in an area of high concentration of militarygunfire-itis imperative for the corpsman to determine the condition ofthe patients blood pressure to determine whether or not he should be fedfluid intravenously. Without a stethoscope which would allow the soldierto be examined in a high noise level area, the corpsman must wait tillthe wounded soldier is evacuated to a point where there is less noisebefore determining the needs of the soldier. In instances where time isof the essence, such as when the soldier has gone into shock, this delaymight prove fatal and could otherwise have been prevented if the patientor soldier could have been examined where he was originally wounded.

Yet another circumstance in which my device would prove invaluable isthe instance where a wounded soldier is being evacuated from the combatarea to a hospital by helicopter. In this latter situation, thevibration of the helicopter, as well as the high noise level associatedwith such types of military aircraft, would prevent the attendingmedical corpsman from determining the soldiers blood pressure. It wouldbe invaluable, and in many instances the difference between life ordeath, if as a result of an examination during the helicopter trip, themedical corpsman could diagnose the patients condition, determine hisneeds and supply these needs en route to the hospital instead of havingto wait until the patient arrived at the hospital before his conditionand needs were determined. For example, if during the trip to thehospital, the corpsman Were able to detect a change in the soldierscondition that required immediate attention, the soldiers needs could befilled and his life would be saved.

My invention overcomes all the difficulties of the prior artstethoscopes which are unusable in high noise level areas by providingmeans for acoustically insulating the stethoscope from any noises thatwould ordinarily have interfered with or prevented its use.

It is, therefore, a principal object of the present inventron to providean improved stethoscope.

Another principal object of the present invention is to provide animproved stethoscope capable of use in areas of high noise level.

Still another principal object of the present invention is to provide animproved stethoscope capable of use in areas of high noise level yetnoted for its convenience.

The features of my invention which I believe to be novel are set forthwith particularity in the appended claims. My invention itself, however,both as to its organization and method of operation, together withfurther objects and advantages thereof, may be best understood byreference to the following description taken in conjunction with theaccompanying drawings in which:

FIG. 1 is one embodiment of my improved stethoscope;

FIGS. 2, 3, 4 and 5 are cross-sections of various portions of theembodiment of FIG. 1;

FIG. 6 is another specie of my invention embodying the principlespreviously set forth; and

FIGS. 7 and 8 are cross-sections of portions of the embodiment of FIG.6.

Referring now to FIGS. 1-4, there is shown my improved stethoscope notedby the fact that it is capable of attenuating aberrant noise. In thisembodiment, stethoscope 10 consists of ear cups 12a and 12b that areheld in place by means of head strap 14 which may be made of aresilient, springy metal so that the ear cups 12a and 12b are maintainedin their relative positions with respect to each other. Along theselines, it should be here added that the connecting strap 14 may be madeadjustable to fit the contour of the head of the user and may beprovided with some sort of padding for the comfort of the user if mydevice is to be used or worn for any extended period.

Ear tubes 18a and 18b are embedded in ear cups 12a and 12b,respectively. Ear tubes 18a and 18b consist of the L-shaped tubeportions 18.1, one end of which passes through the lower end of ear cups12a and 12b to communicate directly with tubing 16a and 16b. The otherend of ear tubes 18.1 terminate in plastic ear pieces 18.2 for insertioninto the users ears. The remainder of ear cups 121; and 12b are filledwith a foamy, resilient, plastic material so that when ear cups 12a and1219 are placed over the users ears, ear pieces 18.2 will fit snuglyinto the auditory canal of each of the users ears and all the parts ofthe pinna or auricle of the ears will fit snugly against the foamymaterial 12.1, thereby excluding aberrant noise.

The lower end of each of the ear tubes 18.1, which passes throughear-cups 12 and 12b, is connected directly to one end of tubing 16a and16b. This tubing is also covered with sound attenuating material 16.1and may be similar to material 12.1 contained within ear cups 12m and12b. By the same token, this connecting tubing may also consist of amore conventional solid rubber tubing with sound attenuating material16.1 wrapped around the outsides thereof.

The other end of tubes 16a and 16b terminates in a pickup unit 22 whichis partially embedded in pickup shell or shield 20. This shield is alsofilled with foamy, resilient, plastic material similar to that containedin ear cups 12a and 12b and is used to shield the diaphragm pickup shownfrom any aberrant noise. It should be noted, in this embodiment, thatthe pickup unit 22 extends slightly above surface 20.2 of shell orshield 20. It is particularly desirable to have the pickup unit protrudePatented May 23, 1967 in this manner so that when the user presses thediaphragm assembly against the patient, he will have to exert additionalpressure to compress material 20.1 and thereby maintain shell or shield20 flush with the patients body. By so doing, the user is assured ofpreventing the aberrant noise from entering into the stethoscope system.

The embodiments as set forth in FIGS. l-5 utilize a dual tube systemwherein both tubes are connected directly to the pickup device.However,. there are some individuals who prefer to use a single tubepickup system in which case the ear tubes are joined to the single tubeby means of a Y connector.

Reference is now made to FIGS. 6 and 7 which depict a single tube pickupsystem in accordance with my invention. In this embodiment, the ear cups12a and 12b are shown joined by the headband 14 as in FIG. 1. However,in this embodiment, tubes 16a and 16b, the ends of which communicatewith car tubes 18a and 18b, respectively, have been foreshortened and,instead of communicating directly with the diaphragm, are now joinedwith tubing 160 by means of Y connector 16.3. As in the embodiment ofFIG. 1, the other end of the tubing terminates at the head of a Bowlesor diaphragm type of pickup unit 22 that is embedded in shield 20 in thesame manner as described with regard to FIG. 5.

While some users prefer the diaphragm type of pickup, it has been foundin the past that many practitioners like, and in certain instancesprefer, the conical type of pickup for various diagnoses.

Reference is now made to FIG. 8 which shows a conical or Bell typepickup unit 24 connected to tubing 16c and covered with a plastic,foamy, springy, acoustic, noise attenuating material 24.2. As in theembodiment shown in FIGS. 1-5, the conical pickup unit 24 (andinsulating material 24.2) is positioned within and extends slightlybeyond the outermost level or lip of hollow shell or shield 24.1. Thus,when my device is in use, the wide or listening opening of the pickupunit is placed against the patient and pressed slightly to compressmaterial.24.2 and exclude aberrant noise.

It should be further noted that a significant attenuation of ambientnoise can be accomplished. by acoustically insulating only either thepickup unit or the connecting tubing and placing ear pieces 18.2directly into the users ears without using ear cups 12a and 12b.However, for

maximum aberrant sound attenuation, the inclusion of ear cups andinsulation for both the pickup and tubing is suggested.

While I have described what is presently considered the preferredembodiments of my invention, it will be obvious to those skilled in theart that various other'changes and modifications may be made thereinwithout departing from the inventive concept, and it is aimed in theappended claims to cover all such changes and modifications as fallwithin the true spirit and scope of my invention.

I claim:

1. A stethoscope comprising sound pick-up means, sound delivery meansfor engaging the ear and means to transport sound from the pick-up meansto the delivery means, said delivery means comprising a cup to cover atleast the major portion of the ear, a tube to extend into the cavity ofthe ear located in said cup and extending through a wall thereof, and asound attenuating material substantially filling said cup and supportingsaid tube therein in a position so that the tube extends beyond the edgeof the cup and the attenuating material so that when the tube is in theear cavity the said material will cover the ear and exclude soundthereto.

2. A stethoscope as in claim 1 wherein said sound attenuating materialis foamed plastic and compressible and will permit movement of the tubetoward the cup.

3. A stethoscope as in claim 1 wherein said pick-up means comprising apick-up unit having a work engaging surface, a concave shell spacedtherefrom and a foamed plastic compressible sound attenuating materialbetween the unit and shell supporting said surface of the unit beyondthe edge of the shell.

4. A stethoscope as in claim 3 wherein said shell has an edge and saidfoamed plastic is compressible so that the said surface of the unit maybe moved to substantially the plane of the edge of the shell.

References Cited by the Examiner UNITED STATES PATENTS 350,393 10/1886Radzinsky 18124 1,203,329 10/1916 Heck l81-24 2,169,806 8/1939 Lian etal 18l24 2,311,416 2/1943 Salb et a1. 181--24 3,192,322 6/1965 Leslie179-1 STEPHEN J. TOMSKY, Primary Examiner.

1. A STETHOSCOPE COMPRISING SOUND PICK-UP MEANS, SOUND DELIVERY MEANSFOR ENGAGING THE EAR AND MEANS TO TRANSPORT SOUND FROM THE PICK-UP MEANSTO THE DELIVERY MEANS, SAID DELIVERY MEANS COMPRISING A CUP TO COVER ATLEAST THE MAJOR PORTION OF THE EAR, A TUBE TO EXTEND INTO THE CAVITY OFTHE EAR LOCATED IN SAID CUP AND EXTENDING THROUGH A WALL THEREOF, AND ASOUND ATTENUATING MATERIAL SUBSTANTIALLY FILLING SAID CUP AND SUPPORTINGSAID TUBE THEREIN IN A POSITION SO THAT THE TUBE EXTENDS BEYOND THE EDGEOF THE CUP AND THE ATTENUATING MATERIAL SO THAT WHEN THE TUBE IS IN THEEAR CAVITY THE SAID MATERIAL WILL COVER THE EAR AND EXCLUDE SOUNDTHERETO.